One problem with the Web is the amount of duplicate content that exists out there. I've worked with clients who have had upwards of 7 and as much as 15 versions of the same page content but with a different URL. We've worked with these clients to address these issues and now the major search engines have introduced a canonical tag to help rid the Web of duplicate pages. Last week the three major search engines announced the canonical tag that can be used to solve duplicate content issues. It's great to see the big three partner on issues such as this.
This canonical tag has been jointly released from the three search engine giants to give your pages the URL format that they all prefer. This is called the Canonical Tag and looks like this:
link rel="”canonical”" href="”http://www.example.com/product.php?item="green-widgets”"
To use this tag, simply add this tag to specify your preferred version of a URL inside the (head) section of the duplicate content URLs:
http://www.example.com/product.php?item=green-widgets&category=widgets
http://www.example.com/product.php?item=green-widgets&trackingid=1234&sessionid=1234
The goal of this canonical tag as Google puts it is:
If your site has identical or vastly similar content that's accessible through multiple URLs, this format provides you with more control over the URL returned in search results.
This is a great step to help cleaning up the Web of duplicate content. For more information from Google visit:
http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
Yahoo's Announcement: http://ysearchblog.com/2009/02/12/fighting-duplication-adding-more-arrows-to-your-quiver/
Microsoft / Live Search: http://blogs.msdn.com/webmaster/archive/2009/02/12/partnering-to-help-solve-duplicate-content-issues.aspx
Labels: canonical tag, duplicate content
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